In recent years, vehicles such as electric vehicles driven by DC power stored in a power storage device are being developed. The method of externally charging the power storage device of such a vehicle is roughly divided into two methods. The first one is to connect a vehicle and charging equipment with a charging cable, transmit a control signal which specifies the upper limit of charging current from the charging equipment to the vehicle, and restrict the charging current to be smaller than or equal to the upper limit (see e.g., Japanese Patent Laying-Open No. 2013-34326 (PTL 1)).
The second method is to extend a charging cord from the vehicle and insert a plug provided at the leading end thereof into an outlet of charging equipment. In the second method, a control signal as in the first method is not used.